Improvement in rock-drills



UNITED STATES PATE 'r QFFIGE.

WILLIAM HOAR, OF FLOYD, IOWA.

IMPROVEMENT IN ROCK-DRILLS.

Specification forming part of Letters Patent No. 156,733, dated November 10, 1874; application filed September 5, 1874.

.To all whom it may concern:

Be it known that 1, WILLIAM Hone, of Floyd, in the county of Floyd and State of Iowa, have invented a new and useful Improvement in Sectional Drills, of which the following is a specification:

The invention will first be fully described, and then pointed out in the claim.

In the accompanying drawing, Figure 1. is a longitudinal section, showing the construction of my improved drill, the section being taken on the line 00 w of-Fig. 2. Fig. 2 is an outside view of the drill. Fig. 3 is a crosssection of Fig. 2, taken on the line 3 y. Fig. 4 is a cross -section taken on the line 2 z of Fig. 2. Fig. 5 is a View of the cutting end of the drill.

Similar letters of reference indicate corresponding parts. 7

A is the main portion of the drill, by which it is attached to the shank B bymeans of the the wings are two mortises, G G, which receive each a gib, H, and key I. The outer ends of these mortises G G are made angular, and the gibs H are made to fit, so that they cannot Work longitudinally when the keys 1 are driven, while angular portions serve to hold the two wings together, as shown in Fig. l. The wings, as well as the main part A, have each a cuttingedge, J, with rightangled lips K, as represented in Fig. 5. The shank B consists of two or more sections, L, put together similar to the links of a chain, but each with a guide or head, m, in which is a groove to fit the sides of the section, to guide and keep them in place. The upper of these sections has a rope-eye, N, and to the lower one the drill is attached by the socket and screw (3, before described.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The combination of drill-section A, having long mortise D E, the wings F F, having each tWo mortises, G Gr, the gibs H, and the keys I, as and for the purpose specified.

WILLIAM HOAR.

Witnesses:

M. EUGENE HOAR, E. I). ABBOTT. 

